Free today from Amazon: McCreed's Law by L.J. Martin. Published by Pinnacle in mass market paperback (2006) and Thorndike in hardcover (2007).

Quote:

Gone, a shipment of gold and a handful of passengers from the transcontinental. Found, one man who has the skill, motivation and courage to track down the mad dog outlaws who hit the train. Now the U.S. Army and detective Morris Flannigan have invited the devil to join their detail--bringing lawless Kane McCreed into the hunt for a band of savage criminals. McCreed plans on laying down his own brand of law...or dying for the one brand of justice he can understand. And he doesn't plan to have any McCreed's die in the process.